Determination of 3,4-dihydroxyphenylalanine (DOPA) in plasma and cerebrospinal fluid by high performance liquid chromatography with electrochemical detection

We report a reliable method for determining DOPA levels in plasma and cerebrospinal fluid. The method is based on complete conversion of DOPA to dopamine and quantification by HPLC-ECD of the dopamine formed. Lower limit of detection was 0.5 nmol/l. No differences in plasma DOPA levels were found between normal children (0-15 yr, n = 60), normal adults (n = 39) and patients with essential hypertension (n = 40) or Parkinson's disease (no DOPA therapy, n = 30). In normal individuals and in patients with essential hypertension venous plasma levels were higher than arterial levels (10.2 vs 9.3 nmol/l, p less than 0.001, V/A ratio 1.11 (SD 0.08), n = 15). Sympathetic stimuli (standing, tilting, bicycle exercise, tyramine) did not influence DOPA levels. In untreated depressed patients (n = 10) and in non-parkinsonian neurological patients (n = 12) cerebrospinal fluid levels of DOPA were 4.5 (SD 2.4) and 5.2 (SD 1.3) nmol/l respectively. A direct method for the measurement of DOPA by HPLC-ECD after deproteinization of plasma is also described and compared with the conversion method. Good agreement was found when plasma DOPA levels exceeded 0.25 mumol/l (y(conversion method) = 0.943x (direct method) + 0.118; n = 60; r = 0.985). The direct method, because of greater simplicity and the possibility of simultaneous measurement of the DOPA metabolite 3-O-methyldopa, is the method of choice with plasma samples from DOPA-treated patients. In non-DOPA treated individuals the conversion method is superior and has proved to be an accurate and sensitive method for the determination of DOPA levels in plasma and cerebrospinal fluid.     

Angiotensin Converting Enzyme Inhibitors: Animal Experiments Suggest a New Pharmacological Treatment for Alcohol Abuse in Humans

The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans.     

Pulmonary valve insertion during reoperation for tetralogy of Fallot

Our experience with pulmonary valve insertion during reoperation for residual lesions after initial open repair of tetralogy of Fallot in 15 patients is reported. Preoperatively, 14 patients were in moderate to severe congestive heart failure, and all 15 had decreased right ventricular (RV) function at cardiac catheterization. All 15 patients had pulmonary insufficiency but not as an isolated finding. The most common residual lesions encountered were ventricular septal defect in 9, tricuspid insufficiency in 11, and peripheral pulmonary arterial stenosis in 6. Tissue valves were inserted in all patients. Mean peak RV-left ventricular pressure ratio measured in the operating room decreased from 0.61 +/- 0.10 (+/- the standard deviation) to 0.47 +/- 0.17 (p less than 0.05). There were no operative deaths. At follow-up (mean, 33 months), all but 1 patient were in New York Heart Association Class I or II. Pulmonary valve insertion should be considered during reoperation for tetralogy of Fallot when pulmonary insufficiency and RV failure are present.     

Surgical aspects of the implantation of catheters for acute peritoneal dialysis in premature, newborn and young infants

Ten years experience with acute peritoneal dialysis in 39 preterm-, newborn and small infants shows advantage and low risk of surgically implanted single dacron cuffed silicone catheters compared to trocar catheters.     

Adrenal and pseudoadrenal masses: CT and US findings

Computed tomography (CT) is currently the imaging modality of choice for assessing the morphology of the adrenal glands in adult patients. Much useful information can be gained using CT in disease processes which primarily involve one or both of the adrenal glands, such as adenomas, as well as in entities which secondarily affect the adrenals, such as pituitary or metastatic disease. The size and configuration of the glands can be readily determined, and masses may be detected. We discuss CT of normal and abnormal adrenal glands with sonographic (US) and pathological correlation, when available. Entities which may mimic adrenal abnormalities are emphasized. Relative advantages of US over CT in the pediatric patient are discussed.     

Memory clinic attenders: A review of 150 consecutive patients

The Dundee Memory Clinic was established in 1991. This paper reviews the diagnosis of the first 150 attenders and compares the findings with those of other memory clinics.